update suse15 to use el8 instead of el7

Author: DrDaveD

ChangeLog

@@ -1,6 +1,7 @@
 - Go back to selecting the cvmfs version from the egi and osg distribution.
 - Properly sort the cvmfs version number from the downloaded list of packages.
 - For osg use 24-main instead of 23-main.
+- For suse15 switch to getting some packages from el8 instead of el7.
 
 cvmfsexec-4.45 - 5 March 2025
 - Change to try downloading cvmfs packages from cvmrepo.s3.cern.ch and

makedist

@@ -167,7 +167,7 @@ fi
 EL=$VERS
 MACH=el$EL
 if [ "$DISTRO" = "suse" ]; then
-    EL=7  # we get some suse stuff from rhel7
+    EL=8  # we get some suse stuff from rhel8
     MACH=sle$VERS
 fi